Although fats, rich in behenic acid, such as BOB or BBO can be made by methods disclosed in the prior art, these methods always have draw-backs which make their product less suitable for application in food products. A conventional route for preparing those fats e.g. is a chemical interesterification (using a base, such as sodium methanolate as catalyst) of a high oleic oil, such as high oleic sunflower and a hardened fat, high in behenic acid, such as hardened high erucic rapeseed oil. However, the products so obtained can only contain maximum 30 wt % behenic acid. Although this content can be increased by a fractionation, such a fractionation would also lead to an increased BBB-content, which would deteriorate the oral properties of the fat.
An alternative route nowadays is an enzymic conversion of fats or of a fat with an acid. We found, that such an enzymic conversion of a fat and an acid leads to products, wherein the triglycerides have high levels of BOB and low levels of BBO. These triglyceride mixtures crystallize readily in the .beta.(v)-stable crystal form. This is a drawback, as these triglcyerides in general have high melting points. Further these .beta.-stable triglycerides are not well compatible with triglycerides that are in .beta..sup.1 -crystalform, as is required for many food-applications, such as spreads. An enzymic process based on the conversion of fats, so e.g. hardened high erucic rapeseed oil with high oleic sunflower oil, will lead to products, that will contain mixed saturated triglycerides such as BStB, while the process further will result in a randomized product from which the composition is determined by the ratio of the starting fats.
Another disadvantage of the above processes, is the uneconomical use that is made of the fatty acids, present in the starting materials. We have studied whether we could find an improved route for the production of triglycerides, rich in behenic acid, wherein the fatty acid residues present in the starting material (e.g. high erucic rapeseed oil) are used in the most efficient way. This new route should enable us to produce triglyceride-compositions, wherein the triglcyerides are predominently in .beta..sup.1 -crystal form so that they combine a high behenic content with an acceptable (or even a good) melt characteristic and are well compatible with .beta..sup.1 -fats in food products. The fats than will be very suitable for application in food products, e.g. as a blend with another fat or oil. It is emphasized here that high behenic contents are very advantageous, as such high contents are believed to make the fats less absorbed by the human-body and thus to make the fats lower calorie-fats.
It should be noted, that BOB-rich triglycerides, that are .beta..sub.2 -stable are disclosed in the Manufact. Confectioneer, November 1989, page 63. These fats are only used in chocolate based materials, because of their .beta..sub.2 -crystal-form.